Projectile launchers have long been popular for a number of purposes, including launching T-shirts as promotional prizes, launching empty beer cans as shooting targets, training retrievers, simulating launched grenades, and launching golf balls or potatoes for the user's entertainment. Examples of prior art projectile launchers include U.S. Pat. No. 3,004,360 to Johnson that launches an empty beer can using the propulsive force of a blank 0.22 cartridge, and the AR15 Golf Ball Launcher manufactured by NcSTAR, Inc. of City of Industry, Calif.
While the prior art projectile launchers largely achieve their goals of launching the projectiles each is designed to launch, they both have significant disadvantages. The '360 patent's use of 0.22 blank cartridges was suitable for launching empty flat top steel beverage cans made in the 1960s when the invention was developed, but modern empty lightweight aluminum cans are likely to be crushed by the propulsive force of a 0.22 blank cartridge. The '360 patent also relies on the presence of an external bead on the can to create a seal with a ring of resilient material to build pressure, which does not exist on modern empty lightweight aluminum cans. The pressure buildup is also potentially variable depending on an individual blank cartridge's characteristics, a can's dimensions, and the condition of the ring. The pressure build up is also insufficient to launch a full can.
The '360 patent uses a combustion chamber that closely receives a blank 0.22 cartridge with the described intention of preventing the use of loaded ammunition instead of a blank cartridge. However, a production model of the invention was reportedly tested by Australian police in 1965 and found to be capable of firing a 0.22 bullet if a can is not in place. The '360 patent's ability to fire live ammunition would greatly increase dangers associated with use of the '360 patent and likely subject it to firearm regulations.
The NcStar, Inc. launcher uses 5.56 blank cartridges to launch golf balls. It has the disadvantage of requiring the use of a fully functional AR-15, M4, or M16 rifle without providing any ability to prevent the use of live ammunition with the launcher instead of blank cartridges. It also does not retain the golf ball until a gas pressure above a selective amount builds up behind the golf ball.
Therefore, a need exists for a new and improved projectile launcher that retains a projectile until a selected amount of gas pressure accumulates behind the projectile and prevents the use of live ammunition with the launcher. In this regard, the various embodiments of the present invention substantially fulfill at least some of these needs. In this respect, the projectile launcher according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in doing so provides an apparatus primarily developed for the purpose of retaining a projectile until a selected amount of gas pressure accumulates behind the projectile and preventing the use of live ammunition with the launcher.